Pen type drug injection device with low friction dose encoder mechanism on thread

Abstract

A drug delivery device comprises a body component located concentrically within a sleeve, wherein the body component comprises body component thread features and the sleeve comprises sleeve thread features that engage with the body component thread features such that the body component is caused to rotate within the sleeve as the body component and the sleeve component move axially with respect to one another by force of an engaging face of the sleeve thread features against an engaging face of the body component thread features causing sliding of the engaging face of the sleeve thread features over the engaging face of the body component thread features. One of the body component and the sleeve constitutes a first part and the other of the body component and the sleeve constitutes a second part. A conductive track pattern is formed on the thread features of the first part and plural contacts are formed on the second part such as to contact the conductive track pattern as the body component rotates within the sleeve.

The invention claimed is: 
     
       1. A drug delivery device comprising:
 a body component located concentrically within a sleeve, wherein the body component comprises body component thread features and the sleeve comprises sleeve thread features that engage with the body component thread features such that the body component is caused to rotate within the sleeve as the body component and the sleeve component move axially with respect to one another by force of an engaging face of the sleeve thread features against an engaging face of the body component thread features causing sliding of the engaging face of the sleeve thread features over the engaging face of the body component thread features, 
 wherein the body component is an inner housing, 
 wherein one of the body component and the sleeve constitutes a first part and the other of the body component and the sleeve constitutes a second part, and 
 wherein a conductive track pattern is formed on the thread features of the first part and plural electrical contacts are formed on the second part such as to contact the conductive track pattern as the body component rotates within the sleeve. 
 
     
     
       2. The drug delivery device as claimed in  claim 1 , wherein the conductive track pattern comprises:
 a continuous portion that extends helically on the first part and that is not in direct contact with the plural electrical contacts formed on the second part as the body component rotates within the sleeve, and 
 a discontinuous portion that extends helically on the first part, that is connected to the continuous portion of the conductive track pattern and that is in direct contact with the plural electrical contacts formed on the second part as the body component rotates within the sleeve. 
 
     
     
       3. The drug delivery device as claimed in  claim 2 , wherein the discontinuous portion of the conductive track pattern is provided on the engaging face of the thread component of the first part and wherein the continuous portion of the conductive track pattern is provided on a non-engaging face of the thread component of the first part. 
     
     
       4. The drug delivery device as claimed in  claim 1 , wherein first and second conductive track patterns are formed on the thread features of the first part, and
 wherein the plural electrical contacts are formed on the second part such as to contact the first and second conductive track patterns as the body component rotates within the sleeve. 
 
     
     
       5. The drug delivery device as claimed in  claim 1 , wherein the conductive track pattern consists of a single conductive track pattern. 
     
     
       6. The drug delivery device as claimed in  claim 1 , wherein the sleeve thread features form parts of first and second ones of different start threads and wherein the sleeve thread features and the body component thread features form parts of first and second ones of different start threads. 
     
     
       7. The drug delivery device as claimed in  claim 1 , wherein the thread features of each thread of the first part includes a conductive track pattern and wherein the thread features of each thread of the second part includes respective plural electrical contacts. 
     
     
       8. The drug delivery device as claimed in  claim 1 , wherein the body component constitutes the first part and wherein the sleeve constitutes the second part. 
     
     
       9. The drug delivery device as claimed in  claim 1 , wherein the sleeve constitutes the first part and wherein the body component constitutes the second part. 
     
     
       10. The drug delivery device as claimed in  claim 1 , wherein each of the plural electrical contacts is sprung, thereby to provide a preload force between the sleeve thread features and the body component thread features. 
     
     
       11. The drug delivery device as claimed in  claim 1 , further comprising a processor configured to receive and interpret electrical signals from each of the plural electrical contacts to determine the position of the cylindrical member relative to the housing. 
     
     
       12. The drug delivery device as claimed in  claim 11 , further comprising a display in communication with the processor, wherein the processor is configured to cause the display to display information determined by the processor based on the electrical signals. 
     
     
       13. The drug delivery device as claimed in  claim 1 , wherein the plural contacts are spring biased in a direction towards the conductive track pattern. 
     
     
       14. The drug delivery device as claimed in  claim 1 , further comprising an outer housing,
 wherein the sleeve and the inner housing are in the outer housing. 
 
     
     
       15. The drug delivery device as claimed in  claim 2 , wherein the discontinuous portion comprises a plurality of conductive segments and a plurality of non-conductive segments, and
 wherein the plurality of conductive segments and the plurality of non-conductive segments are arranged in an alternating pattern such that successive ones of the plurality of conductive segments are separated by a respective one of the non-conductive segments. 
 
     
     
       16. The drug delivery device as claimed in  claim 2 , wherein the continuous portion couples the discontinuous portion to a battery. 
     
     
       17. The drug delivery device as claimed in  claim 1 , wherein the engaging face of the body component and the engaging face of the sleeve are transverse to a longitudinal axis of the body component and the sleeve. 
     
     
       18. The drug delivery device as claimed in  claim 1 , wherein the body component is a hollow cylinder. 
     
     
       19. The drug delivery device as claimed in  claim 18 , further comprising a spindle arranged in the hollow cylinder of the body component. 
     
     
       20. The drug delivery device as claimed in  claim 1 , wherein the body component comprises a plastic material,
 wherein, when the body component is the first part, the conductive track pattern is on an exterior surface of the plastic material, and 
 wherein, when the body component is the second part, the plural contacts are on the exterior surface of the plastic material.